Printing apparatus for photographic purposes



March 10, 1931. o. aARNAcK PRINTING' APPAMTU S FOR PHOTQGRAPHIC PURPOSESFiled April 6'. 1929 INVENTOR Patented Mar. 10, 1931 UNITED STATESPATENT OFFICE OSKAR BARNACK, OF WETZLAB, GERMANY, ASSIGNOR TO THE FIRMOI ERNST LEITZ, OPTISOHE WERKE, O1 WETZLAIR, GERMANY PRINTING APPARATUSFOR PH O'I'OGRA PHIG PURPOSES Application filed April 6, 1929, SerialNo. 353,092, and in Germany October 22, 1988.

This invention relates to an apparatus for arrangement of the abovementioned transprinting diapositives from photographic negparent platesit becomes possible to look right atives, in which the use of a sourceof light through the whole apparatus, at the same in the interior of theapparatus is supertime allowing to inspect the film contained fl thereinand to judge the time of exposure re- My invention attains this bymodifying the quired for the diapositive copy, without apparatus in sucha manner that it contains a necessitating a source of light inside theaptransparent exposure chamber enabling a paratus. 0 perfect control ofthe film to be copied. Having described my invention, I declare Theaccompanying drawing represents an that what I claim 1s: apparatus thatembodies the improvement. A dev1ce for pr nting dlapositives from Inthis drawing one side wall of the apparaphotographic negatives,consisting of a castus, which is in reality fitted with a removing withtwo film chambers, a film moving able lid, is shown open in order toillustrate roll, a window in the back wall of the casing,

the interior of the apparatus. In a casing 1 another window arranged onsprings in the 65 is at one end a film keeping chamber 2 and front wallof the casing, a cover movably at the other vend a film winding chamber3, hinged on to the front wall, and an addiboth separated, by opaquepartitions 4, 5, tional window in the cover that, when being from theexposure chamber 6. The two cham-' closed, presses against the beforementioned bers 2 and 3 can be closed light-tight by the wlnflow based onsprings. 79 cover 7, which is fixed to the casing 1 by a Signed at anol'b-olrthe-Main, Gerhinge 8. This hinged cover and the back wall many,t s 8t day of March, A- D. 1929. of the casing have each a window 31, 9,which OSKAR BARNACK. may be fitted with transparent glass plates 12, 13,filters or the like in frames 10, 11 and 29, 30. A similar transymrentplate 23 is arranged in the front wall adjacent to the cover. A filmstrip 17 leads through slits 14, 25 in the front wall of the casing overtwo slide bars 15, 16 and over a film moving roll 18.

The latter is provided atone end with a knob 19 to be acted by hand. Inturningthis knob 19 the teeth 20 of the roll engage into theperforations 26 of the film strip and move the latter from one chamberinto the other.

The slide bars 15, 16 and the film moving roll j 18 project a littlebeyond the surface of the "a transparent plate 23 which rests on springs21, 22, so that, as long as the hinged cover 7 is not folded down, thefilm will not touch I the transparent plate 23. Only after the cover hasbeen pressed down, the windowplate 31 projecting inside the cover holdsa part of the film stri in contact with the 45 trans arent plate 23. hefilm is thus firmly kept tween the two transparent plates 12 and 23, andtogether with the negative film to be copied, which has its place in thegrooves 27. 28 of the window frame 10, 11.

The nature of this invention is that by the mi

